This invention relates to a quick releasing clamping device wherein a half nut is engaged with screw or disengaged from the screw by rotation of the screw.
Common clamping devices, particularly vises, include a pair of opposing jaw members which are brought into engagement with each other or moved away from each other by rotation of a screw which interconnects the members. A relatively fine thread is frequently used on the screw in order to increase the clamping force. This means that moving the jaw members apart by rotation of the screw is a relatively slow process. Quick release mechanisms have therefore been developed to move the jaw members apart more quickly. Prior art devices of this type typically include a screw rotatably mounted on one of the members and a half nut mounted on the other member. A separate lever on the front of the vise can move the half nut into engagement with the screw or move the half nut away from the screw. In this way the vise is capable of quick release as well as instantaneous grip. However, it should be noted that the operation of such a vise may require two hands: one to move the lever and the other to move the jaws of the vise.
For some purposes it is desirable to provide single-handed operation of the vise. This could be achieved by a quick release and instantaneous grip mechanism operated by the handle typically connected to the screw.